As portable electronic devices become more compact, and the number of functions performed by a given device increase, it has become a significant challenge to design a user interface that allows users to easily interact with a multifunction device. This challenge is particularly significant for handheld portable devices, which have much smaller screens than desktop or laptop computers. This situation is unfortunate because the user interface is the gateway through which users receive not only content but also responses to user actions or behaviors, including user attempts to access a device's features, tools, and functions. Some portable communication devices (e.g., mobile telephones, sometimes called mobile phones, cell phones, cellular telephones, and the like) have resorted to adding more pushbuttons, increasing the density of push buttons, overloading the functions of pushbuttons, or using complex menu systems to allow a user to access, store and manipulate data. These conventional user interfaces often result in complicated key sequences and menu hierarchies that must be memorized by the user.
Many conventional user interfaces, such as those that include physical pushbuttons, are also inflexible. This is unfortunate because it may prevent a user interface from being configured and/or adapted by either an application running on the portable device or by users. When coupled with the time consuming requirement to memorize multiple key sequences and menu hierarchies, and the difficulty in activating a desired pushbutton, such inflexibility is frustrating to most users.
Portable electronic devices commonly provide a lighted display so users can interact with their applications and the device in bright daylight or at night. Because battery life is critical for portable devices, and because displays use much more power when lighted than when dimmed, portable devices commonly include a timeout feature wherein a lighted display is dimmed following a preset time period of user inactivity. For example the device display could be dimmed a minute after a user completes a call and subsequently does not interact with the device. This dimming feature can be annoying to users when the nature of their interaction with the device is periodic—in which situation they are required to continually interact with the device (e.g., touch the display or button) to relight the display. For example, consider the situation where a user watching a video on a portable device needs continually to touch the device to restore the screen's illumination. A user can increase the timeout period associated with display dimming, but this would have a deleterious effect on battery life and might not be appropriate in all situations.
Thus, there is a need for portable electronic devices that provide improved user interfaces and capabilities through which display dimming is managed.